642 Abdomen (Cont.) Differential Diagnosis of Abdominal s E. Focal parenchymal calcification of the kidney Tuberculosis (Fig. 27.19) Adenocarcinoma (Fig. 27.20) Nephroblastoma (Wilms tumor) (Fig. 27.21) Xanthogranulomatous pyelonephritis (Fig. 27.22) May appear as a single nodular or irregular calcification (see above). About 10 % of renal adenocarcinomas calcify. If a renal mass contains calcium in a nonperipheral location, it is very likely malignant. Even a curvilinear cystic peripheral calcification of a mass does not exclude malignancy. Cystic, streaky, or amorphous calcification of the tumor is uncommon, but may occur in older children and adults with nephroblastoma. Simulates carcinoma, but inflammatory masses may be multiple and diffusely calcified. A large pelvic calculus is present in the majority of cases, causing pelvocaliceal obstruction. (continues on page 643) Fig. 27.19 Renal tuberculosis of the left kidney with focal calcification. The calcification appears cystic but internal calcifications are also present. Fig. 27.20 Adenocarcinoma of the left kidney with calcification a thick-walled, somewhat cystic calcification with irregular internal calcific deposits. Fig. 27.21 A large Wilms tumor in the right kidney of a threeyear-old boy, seen as an enlarged, nonexcreting kidney containing tiny flecks of calcification. Fig. 27.22 Xanthogranulomatous pyelonephritis. Scout film shows pelvic stones and parenchymal calcifications.
27 Abdominal s 643 (Cont.) Differential Diagnosis of Abdominal s F. Cystic (curvilinear) renal calcification Simple renal cyst (Fig. 27.23) Adenocarcinoma (Fig. 27.24) Polycystic or multicystic disease (Fig. 27.25) Echinococcal cyst Organized perirenal hematoma (Fig. 27.26) Old perirenal abscess Nephroblastoma (Wilms tumor) A thin curvilinear calcification can be demonstrated in 3 %. 20 % of thin curvilinear calcifications are due to a calcified fibrous pseudocapsule of a renal adenocarcinoma. Curvilinear calcifications similar to that of a simple cyst may occur. The majority are calcified. Complete circumferential ring of calcium is characteristic but not always present. May appear as large cystlike calcification. May appear cystic due to peripheral calcification. (continues on page 644) Fig. 27.23 Two calcified simple renal cysts in the right kidney (arrows) are seen. Fig. 27.24 Adenocarcinoma of the kidney. Curvilinear calcification (with possible internal calcifications) in a large tumor of the lower pole of the right kidney. Fig. 27.25 Polycystic kidneys with renal failure and calcification of the cyst walls bilaterally. Fig. 27.26 of an organized perirenal hematoma on the left.
644 Abdomen (Cont.) Differential Diagnosis of Abdominal s Ureteral calcification Renal artery aneurysm Renal milk of calcium DD: Residual Pantopaque from prior cyst puncture and Pantopaque injection Ureteral calculus: Mostly idiopathic but the following conditions predispose: Decreased mobility Pre-existing ureteral obstruction Metabolic diseases (see nephrocalcinosis) Pre-existing infection Postoperative ureteral stump DD: Phleboliths (round, located laterally, and commonly below the interspinous line) Schistosomiasis Tuberculosis (Fig. 27.27) A cracked eggshell-like circular calcification at the renal hilus is seen in about one third of renal artery aneurysms. Calcium-containing sediment in a cyst, caliceal diverticulum, or obstructed renal pelvis. Mimics calculus in supine films. In upright position calcific material gravitates to the bottom of the cyst. Characteristically irregular, often oval, lodged at three levels: Ureteropelvic junction (large calculi) Pelvic brim Ureterovesical junction (small calculi) Stones less than 4 mm will eventually pass spontaneously in over 80 %. 4 6 mm stones will be passed spontaneously in 50 %, but often cause renal obstruction. Stones larger than 6 mm rarely pass spontaneously and have a high incidence of serious complications. Tubular calcification of the distal ureter occurs in about 15 % of patients. Ureter calcifies less frequently than the kidney and its appearance is variable. Ipsilateral renal calcification is often present. Adrenal and retroperitoneal calcification A. Triangular Neonatal adrenal hemorrhage Occurs in infants born to mothers with diabetes and/or with an abnormal obstetric history. The periphery of the adrenal calcifies a few weeks after hemorrhage. Can be an incidental finding. Adrenal tuberculosis (Addison s disease) In about a quarter of patients discrete, stippled densities outline the entire adrenal. can also be confluent and dense. B. Cystic (curvilinear) Adrenal cyst: Lymphatic Necrotic pseudocyst (Fig. 27.28) Cystic adenoma Echinococcal Old hemorrhage (Fig. 27.29) A thin rim of curvilinear calcification above the kidney. C. Mottled mass calcification Adrenal cortical carcinoma Pheochromocytoma (rare) Adrenal cortical adenoma (rare) Adrenal myelolipoma (a small mass of bone marrow and fat) (very rare) Neuroblastoma Retroperitoneal teratoma Retroperitoneal cavernous hemangioma (Fig. 27.30) Scattered flecks of calcification throughout the mass. that is fine granular or stippled, rarely massive, occurs in about 50 % of neuroblastomas. It is the second most common malignancy in children (after Wilms tumor). Calcified spicules of cartilage or bone are seen near the midline of the upper abdomen. Teeth inclusions may be identifiable. A large mass with multiple phleboliths. (continues on page 646)
27 Abdominal s 645 Fig. 27.27 Tuberculosis of the right distal ureter with characteristic ribbon-like calcifications (arrows). Fig. 27.28 Necrotic pseudocyst of the right adrenal. A large cystic calcified mass, separate from the kidney, is seen. Calcified old adrenal hemorrhage above the left kid- Fig. 27.29 ney. Fig. 27.30 Retroperitoneal cavernous hemangioma. Multiple phleboliths superimposed on the calcified and ectatic abdominal aorta and anterior to it are seen.
646 Abdomen (Cont.) Differential Diagnosis of Abdominal s D. Longitudinal tubular calcification Other retroperitoneal tumors (Fig. 27.31) Calcified lymph node(s) Retroperitoneal hematoma Tuberculous psoas abscess Atherosclerosis Abdominal aortic aneurysm (Fig. 27.32) is extremely rare. One or more 1 to 1.5 cm dense, often coarse calcifications. May present as a large calcification. Sclerotic plaques of the aortic wall are common in the elderly. The aorta characteristically narrows toward the bifurcation. It may be curved and simulate an aneurysm. The walls of the aneurysm tend to calcify more than the normal aorta. Calcified plaques outline the aneurysm that most commonly occurs below the renal arteries, Oblique films can be used to avoid superimposition of the spine. (continues on page 647) Fig. 27.32 Calcified abdominal aortic aneurysm. Fig. 27.31 Retroperitoneal teratoma. A large calcified mass originating in the right retroperitoneum with extension into the subhepatic space is seen.
27 Abdominal s 647 (Cont.) Differential Diagnosis of Abdominal s Pelvic calcification A. Tubular calcification Arteriosclerosis The aorta and the iliac arteries are frequently calcified and seen as irregular plaque-like densities. May be seen in young persons with diabetes. B. Calcified bladder wall Vas deferens Associated conditions: Diabetes mellitus Tuberculosis Degenerative change (Fig. 27.33) Schistosomiasis (Fig. 27.34) Tuberculous cystitis Encrusted cystitis: nonspecific infection post-irradiation Bilaterally symmetric tubular densities that run medially and caudally to enter the base of the prostate, somewhat mimicking a medium-sized arteriosclerotic artery. Vas deferens calcification due to chronic inflammation (tuberculosis, syphilis) is intraluminal and has an irregular pattern. About 50 % of patients with schistosomiasis of the bladder have visible calcifications of the bladder, most apparent at the base. A linear opaque shadow may surround a relatively normal-sized bladder. A disruption in the continuity of the homogenous line of calcification is suggestive of a squamous cell carcinoma of the bladder, a common complication. A rare cause of bladder wall calcification. Usually a faint calcified rim is seen in a contracted bladder, associated with calcifications in a kidney and ureter. A very rare cause of calcification of the bladder wall. (continues on page 648) Fig.27.33 Calcified vas deferens in a 65-year-old patient, an incidental finding. Fig. 27.34 a, b a Schistosomiasis of the urinary bladder. A linear calcified ring represents the bladder wall. b The same patient, two years later. The disruption of the right bladder wall calcification is virtually diagnostic for a complicating squamous carcinoma. a b